Apparatus for mixing gaseous fuel with air

ABSTRACT

A system and method for mixing gaseous fuel with air prior to combustion in an internal combustion engine. The system includes an L-shaped channel with a cap mounted to one end and an inlet formed at the other end. A plurality of holes is formed in the L-shaped channel. The channel is mounted to the air intake system of the internal combustion engine upstream from the air filter such that a partial vacuum is created in the vicinity of the holes as the incoming air flows past the channel. The channel includes means for regulating the flow of gaseous fuel through the channel.

BACKGROUND

1. Field of the Invention

The present invention relates to a system and method for mixing gaseousfuel with air, and more particularly, to a system and method for mixinggaseous fuel with air in a dual fuel system of an internal combustionengine.

2. Prior Art

Various types of carburetors have been developed for internal combustionengines to solve the basic problem of mixing liquid gasoline fuel withair to provide a combustible fuel/air mixture. Problems inherent in thecarburetion of liquid fuels have led many to explore gaseous fuels, suchas propane, as an alternative to conventional gasoline or diesel fuels.Thus, many different carburetors or mixers have been developed forgaseous fuel systems.

Much development has occurred particularly in the area of "conversionkits" for gaseous fuel mixers which are adapted for installation in thegasoline fuel carburetion system of an ordinary internal combustionengine. These so-called conversion kits are intended to provide a dualfuel system which will permit operation of the engine on liquid fuelalone, gaseous fuel alone, and in some systems, combinations of the twofuels.

The prior art gaseous fuel mixers can be generally classified ito threecategories based on the type of installation within the combustionengine: (1) mixers which are installed between the intake manifold andthe carburetor; (2) mixers which are installed directly inside of oraround the carburetor; and (3) mixers which are installed within oradjacent the air filter housing so as to release gaseous fuel inside theair filter.

Generally speaking, each of these types of gaseous fuel mixers isdifficult to install. The desired connections are often congested withthrottle linkage, choke linkage, vacuum hoses, fuel lines, valve lines,and the like. Moreover, typically the prior art fuel mixers requirecomplicated adjustments in order to adapt them to the characteristics ofa particular combustion engine.

Another common installation problem is that portions of the originalengine equipment must be replaced or modified to accommodateinstallation of the prior art type mixers. As a result, time-consumingmodifications must be made to the engine. For example, often it ocursthat a gaseous fuel mixer cannot be used with the existing air intakesystem of the combustion engine. This necessitates providing the mixerwith a vacuum-creating device or pressurizing the gaseous fuel beforeinjection into the air flow to obtain an adequate fuel/air mixture.Also, prior art fuel mixers of the third type, those releasing gaseousfuel inside the air filter, are commonly connected to a gaseous fuelline through the top of the air filter housing. Such fuel lineconnections frequently require modification of the car hood toaccommodate the gaseous fuel lines.

Another significant problem experienced with the prior art type fuelmixers is that proper mixing of the gaseous fuel with the air flowinginto the combustion engine is difficult to achieve. The basic problem ishow to combine the fuel and air particles into a homogeneous mixture. Animportant factor in achieving a homogeneous mixture of fuel and air isthe path of the air flow in relation to the entry of the gaseous fuelinto the air flow. In nearly every internal combustion engine, the airflow is irregular between the air filter and the engine cylinders, andsince most prior art fuel mixers use the existing air flow system of theinternal combustion engine, some of the engine cylinders receive aricher gaseous fuel/air mixture than other cylinders. Thus, tocompensate, the rate of gaseous fuel injection into the air flow isincreased so that combustion will still occur within the cylindersreceiving the leanest air/fuel mixture. By adjusting the rate of fuelflow to provide the leanest cylinder with an optimum air/fuel mixture,the other cylinders consequently receive a richer air/fuel mixture thanis necessary for combustion, resulting in wasted fuel and poor engineefficiency. This problem is compounded by the fact that in many cases,the very installation of the prior art type gaseous fuel mixers tends torender the incoming air flow more irregular.

A further problem of nearly every prior art type mixer is thatadditional gaseous fuel is wasted during acceleration of the engine dueto the effect of the engine vacuum during the air response delay betweenthe engine cylinders and the air inlet of the air intake system.Typically, when a driver depresses the accelerator pedal of his vehicleto accelerate the engine, a series of butterfly valves in the carburetorare opened to allow more fuel/air mixture to enter the cylinders, thusincreasing the power output of the engine. Upon opening these valves,the air flow within and immediately around the carburetor is suddenlyexposed to a vacuum created by the engine pistons. The influence of thevacuum is transferred back through the engine's air flow system untilsatisfied by the incoming air that is drawn through the air intake. Withthe prior art type mixers, this momentary vacuum imposed on the priorart type mixers causes additional fuel to exit the fuel mixing deviceand mix with the air flow, thus yielding a gaseous fuel/air mixturewhich is considerably richer than the optimum mixture needed forcombustion. As a result, the excess gaseous fuel injected into the airflow is wasted. And when the air filter of the internal combustionengine is dirty or becomes wet, the air flow is further impeded and evenmore gaseous fuel is wasted due to a longer air response delay duringacceleration.

In view of the foregoing, what is needed in the art is a gaseous fuelmixer for a dual fuel system of an internal combustion engine thatovercomes these and other problems of the prior art, and yet iseconomical and simple to construct and install.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION

The present invention relates to a system and method for mixing gaseousfuel with air for subsequent combustion in a dual fuel combustionengine. The gaseous fuel mixer includes a channel with a cap mounted toone end and an inlet formed at the other end thereof. The gaseous fuelmixer is mounted to the air intake system of an ordinary internalcombustion engine at a position before the air filter. The cap ispositioned outside the air intake system so as to support the channelwithin the air intake system. The inlet is connected to a fuel linewhich is in communication with a gaseous fuel source.

The fuel line introduces gaseous fuel into the inlet at atmosphericpressure. A series of holes is formed in a portion of the channel and issituated within the air intake system so as to point downstream from theair flowing through the air intake system. As incoming air rushes pastthe holes formed in the channel, a partial vacuum is created near theholes, drawing the gaseous fuel from the channel into the air intakesystem. As the rate of air flow through the air intake system increases,the amount of gaseous fuel drawn through the holes into the air intakesystem increases proportionately. Thus, the ratio of gaseous fuel to airwithin the air intake system always remains essentially constant. Anadjustable flow regulator mounted to the channel allows the user toadjust the flow of gaseous fuel into the channel.

It is, therefore, an object of the present invention to provide agaseous fuel mixing system for mixing propane or other gaseous fuel in adual fuel system of an internal combustion engine.

It is another object of the present invention to provide a gaseous fuelmixer which is quickly and easily installed into the air intake systemof an internal combustion engine without elaborate modification of theexisting engine system or cumbersome and time-consuming installationprocedures.

Still another object of the present invention is to provide a gaseousfuel mixer which is inexpensive and of simple construction, requiring noprecision machining in the manufacture thereof, and which is thusinexpensive and yet highly effective in achieving its intended result.

A further object of the present invention is to provide a gaseous fuelmixing system which achieves nearly perfect mixing of the gaseous fuelwith air before the gaseous fuel/air mixture reaches the cylinders ofthe internal combustion engine.

Yet another object of the present invention is to provide a gaseous fuelmixing system which provides a constant gaseous fuel/air ratioirrespective of increased impedance to the air flow caused by the airfilter and the cylinders of the engine system.

Still another important object of the present invention is to provide agaseous fuel mixing system which achieves high fuel economy during theoperation thereof.

Yet a further object of the present invention is to provide a highlyeffective method for mixing gaseous fuel with air in a dual fuel systemof an internal combustion engine.

These and other objects and features of the present invention willbecome more fully apparent from the following description and appendedclaims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of one presently preferred embodimentof the present invention, with portions broken away to reveal interiorconstruction.

FIG. 2 is a front elevational view of a second preferred embodiment ofthe present invention.

FIG. 3 is a side elevational view of a third preferred embodiment of thepresent invention.

FIG. 4 is a schematic illustration of one presently preferred method ofusing the apparatus of the present invention in a dual fuel combustionengine.

FIG. 5 is a top plan view of FIG. 4, showing the position of theinstalled gaseous fuel mixer and alternative installation positions inthe air intake system.

FIG. 6 is a partial cross-sectional view showing another preferredembodiment of the gaseous fuel mixer of the present invention installedwithin the snorkel of the air intake system of a combustion engine.

FIG. 7 is a partial cross-sectional view showing yet another preferredembodiment of the gaseous fuel mixer of the present invention mounted tothe snorkel of the air intake system of an internal combustion engine.

FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to the figures wherein like parts are designatedby like numerals throughout.

A first preferred embodiment of the gaseous fuel mixer of the system ofthe present invention, generally designated 10, is illustrated inFIG. 1. The gaseous fuel mixer 10 includes a hollow L-shaped channelwhich is formed by connecting a first channel member 16 to a secondchannel member 12. Channel member 12 is attached to channel member 16 bya series of threads 30 formed in the lower end of channel member 12. Acap 14 is mounted to the upper end of channel member 12 by glue, epoxy,or other suitable means. First channel member 16, second channel member12, and cap 14 can be formed from any material which is resistant tocorrosion by the gaseous fuel, as for example, polyvinyl chloride (PVC),fiberglass, plastics, certain types of metals, ceramics, or epoxies.

A plurality of holes 18 are formed in the second channel member 12 asshown in FIG. 1. Holes 18 can be arranged in any desirable pattern;however, it has been found advantageous to arrange holes 18 in a singlerow so as to be diametrally opposite the surface of second channelmember 12 which is first contacted by the air flow, as will be explainedin more detail herein.

A gaseous fuel inlet 22 is formed in one end of first channel member 16.A series of ridges 20 is also formed near the end of first channelmember 16 to provide an anchoring surface for a gaseous fuel line to beattached thereto.

An adjustable screw 24 is used to regulate the flow of gaseous fuelthrough first channel member 16, and subsequently, through secondchannel member 12. Adjustable screw 24 has a series of threads 28 forconnection to the first channel member 16. A nut 26 is used to securescrew 24 to first channel member 16 at any desirable position. Byadjusting the screw 24 the impedance within first channel member 16 maybe increased or decreased so that the rate of gaseous fuel flowingthrough first channel member 16 can be correspondingly increases ordecreased, thus regulating the flow of gaseous fuel through secondchannel member 12 and out holes 18.

A second preferred embodiment of the gaseous fuel mixer of the system ofthe present invention, generally designated 11, is illustrated in FIG.2. This embodiment is identical to the embodiment of FIG. 1 except thatthe embodiment of FIG. 2 includes a plurality of rectangular holes orslits 18a formed in the second channel member 12. Slits 18a areillustrative of the various configurations which can be used to form theoutlet in second channel member 12. Other suitable configurations couldalso be used, as for example, a continuous slit (not shown) extendingthe length of the area covered by slits 18a in FIG. 2. Thus, it will beappreciated that any number of configurations are possible in formingone or more outlets in second channel member 12 in implementing theinventive concepts of the present invention.

A third preferred embodiment of the gaseous fuel mixer of the system ofthe present invention, generally designated 13, is shown in FIG. 3. Thispreferred embodiment is also identical to the embodiment of FIG. 1except that instead of an adjustable screw 24 and position-fixing nut 26to regulate the flow of gaseous fuel through first channel member 16,the embodiment of FIG. 3 includes a stopcock generally designated 31 toregulate the flow of gaseous fuel through first channel member 16.Stopcock 31 comprises a handle 32 and a rotatable member 34 having abore 36 formed therein. Stopcock 31 is mounted to first channel member16 such that stopcock handle 32 is disposed outside channel member 16and rotatable member 34 is disposed within channel member 16. Thediameter of rotatable member 34 corresponds to the diameter of firstchannel member 16. By turning stopcock handle 32, bore 36 can bepositioned to increase or decrease the rate of gaseous fuel flowingthrough the first channel member 16, and subsequently through the secondchannel member 12. Maximum fuel flow is achieved by positioning bore 36parallel with the walls of first channel member 16. Minimum fuel flows,or effectively no fuel flow, is accomplished by positioning bore 36perpendicular to the walls of first channel member 16.

It will be appreciated that various other flow-regulating devices may beused in lieu of adjustable screw 24 of FIG. 1 or stopcock of FIG. 3.

The installation of the gaseous fuel mixer in the air intake system ofan internal combustion engine is best viewed in FIG. 4. Although thegaseous fuel mixer illustrated in FIG. 4 corresponds to the embodimentof FIG. 3, the preferred embodiments of FIGS. 1 and 2 would be installedinto the air intake system in an identical manner. The gaseous fuelmixer 13 is mounted to a snorkel 15 which is formed as an extension ofan air filter housing 40 of the air intake system. Air filter housing 40represents the air filter housing of any ordinary vehicle and has a lid41 secured to the top thereof by a wing nut 43 as well as an air filter42 disposed within the housing 40. Similarly, snorkel 15 represents thesnorkel of any ordinary vehicle and has an inlet 17 for receivingincoming air.

Referring still to FIG. 4, the gaseous fuel mixer is installed into theair intake system by first drilling holes through the top and bottomsurfaces of snorkel 15 which correspond to the diameter of secondchannel member 12. Cap 14 is mounted to second channel member 12 and thecap/channel member assembly is inserted into the top hole of snorkel 15such that holes 18 face directly opposite snorkel inlet 17. Firstchannel member 16 is screwed onto the end of second channel member 12 atthreads 30 and positioned against the bottom surface of snorkel 15 tocooperate with cap 14 in securing second channel member 12 within thesnorkel 15. It may also be desirable to apply a silicone compound aroundthe base of cap 14 and first channel member 16 to provide a leakproofseal between the gaseous fuel mixer and snorkel 15. A gaseous fuel line38 is inserted over the end of first channel member 16 and is secured inplace by the ridges 20 formed at the end of first channel member 16.Gaseous fuel line 38 is additionally secured to first channel member 16by a conventional screw clamp 37.

Referring now to FIG. 5, the gaseous fuel mixer can be installedanywhere along the air intake conduit, generally designated 62, of theair intake system. The air intake conduit 62 includes snorkel 15 and aram induction conduit 66 terminating at an air inlet 64. Ram inductionconduit 66 is connected to snorkel 15 at snorkel inlet 17 so that airentering air inlet 64 passes through ram induction conduit 66, intosnorkel 15, and subsequently into air filter housing 40.

The various possible installation positions for the gaseous fuel mixerare illustrated in FIG. 5 by the position of the cap 14 and alternativecap positions 14a-14g shown by dashed lines. Alternative cap position14a represents positioning of the gaseous fuel mixer just inside airfilter housing 40 but still before the air filter 42 shown in dashedlines. Alternative cap positions 14b, 14c, and 14d represent alternativepositioning of the gaseous fuel mixer within snorkel 5. Alternative cappositions 14e, 14f, and 14g represent alternative positioning of thegaseous fuel mixer within the ram induction conduit 66. It will thus beapparent that the gaseous fuel mixer may be mounted to the air intakesystem at any position from air inlet 64 to air filter 42. The internalcombustion engine 58 and vehicle body 60 are included to illustrate theenvironment of the system of the present invention.

One presently preferred method of using the gaseous fuel mixer is alsounderstood by reference to FIG. 4. FIG. 4 schematically illustrates thedual fuel system for the internal combustion engine 58. The liquidgasoline fuel system and the gaseus fuel system can be used alone or incombination to operate the internal combustion engine 58.

The liquid gasoline fuel system illustrated in FIG. 4 is typical of thetype of gasoline fuel systems used in most internal combustion engines.A gasoline carburetor 44 communicates with air filter housing 40 toreceive incoming air after filtration by air filter 42. A plurality ofventuries 46 are formed within carburetor 44 and provide passageways forthe air which will be directed to each of the engine cylinders. Liquidgasoline from the gas tank is introduced into the venturies 46 through aliquid fuel line 52 that is connected through valve 51 to fuel lines 50.Fuel lines 50 lead to gasoline reservoirs 49 and fuel lines 48 leadingto each of the venturies 46. As air is directed downward from air filterhousing 40 through venturies 46, liquid gasoline is introduced fromgasoline fuel lines 48 into the venturies and mixed therewith forsubsequent combustion in the cylinders. Valve 51 is installed betweenthe gaseous fuel lines 52 and 50 to provide a means for selectivelyshutting off or opening up the flow of liquid gasoline from fuel line 52into fuel lines 50.

The gaseous fuel system includes a conventional converter 56 forconverting liquid fuel such as liquid propane to a gaseous state. Itwill be appreciated that any combustible gaseous fuel such as hydrogengas, methane gas, natural gas, or the like, may be used with the gaseousfuel system and gaseous fuel mixer of the present invention. Converter56 also includes a conventional diaphragm means (not shown) forintroducing the gaseous fuel into a gaseous fuel line 55 at atmosphericpressure. A valve 54 is positioned between the gaseous fuel lines 55 and38 to provide means for selectively shutting off or opening up the flowof gaseous fuel from gaseous fuel line 55 into gaseous fuel line 38.

With valve 54 in the open position, gaseous fuel is introduced throughgaseous fuel line 55 into gaseous fuel line 38 and channel members 16and 12. As incoming air flows through snorkel 15, it strikes the leadingsurface of second channel member 12 causing the air flow to be divertedaround the second channel member 12. The air flowing past holes 18creates a partial vacuum in the vicinity of holes 18. This vacuum isenhanced by the increased cross-sectional configuration of snorkel 15,which is typical of the snorkels found in most vehicles. Since the airflowing through snorkel 15 is also near atmospheric pressure, the vacuumimposed around holes 18 results in a pressure differential between thegaseous fuel within second channel member 12 and the area within snorkel15 immediately proximate to holes 18, thus drawing the gaseous fuel fromsecond channel member 12 through holes 18 and into snorkel 15 to mixwith the air flow.

The air entering air intake conduit 62 (see FIG. 5) through air inlet 64is maintained at atmospheric pressure regardless of the speed of thevehicle by positioning air inlet 64 perpendicular to the line ofmovement of the vehicle 60. Thus, the rate of the air flow through airintake conduit 62 is determined solely by the demand of the enginecylinders. As the engine cylinders work harder and require more air, theair flow through snorkel 15 increases and the vacuum imposed aroundholes 18 increases proportionately, causing the gaseous fuel mixer torelease a proportionately greater amount of gaseous fuel into thesnorkel 15. Conversely, when the air demand of the engine is decreased,the vacuum imposed around holes 18 and the amount of fuel released intosnorkel 15 decrease in proportion to the decrease in the air flowthrough snorkel 15. Thus, irrespective of the rate of the air flowthrough snorkel 15, the same gaseous fuel/air ratio is achieved by thegaseous fuel mixer.

Once it enters the snorkel 15, the gaseous fuel mixes with the air toform a combustible gaseous fuel/air mixture. To ensure that the optimumratio of gaseous fuel to air is obtained for combustion, the flow ofgaseous fuel through the gaseous fuel mixer is adjusted by turninghandle 32 of stopcock 31 as described above.

The gaseous fuel/air mixture next enters air filter housing 40 where itis filtered by air filter 42 before passing into carburetor 44. Airfilter 42 not only filters out foreign particles within the gaseousfuel/air mixture, but also mixes the gaseous fuel and air into a nearlyperfect homogeneous mixture. This is thought to be due, in part, to theextremely small openings in air filter 42 through which the gaseous fueland air must pass. By the time the gaseous fuel/air mixture passesthrough the carburetor 44 and into the cylinders of the internalcombustion engine, the mixture of the gaseous fuel with the air isnearly perfect, with the result that all engine cylinders receivesubstantially the same ratio of gaseous fuel to air for subsequentcombustion thereof. Thus, stopcock 31 can be adjusted so that eachcylinder ultimately receives the optimum gaseous fuel/air mixture forcombustion, resulting in exceptional fuel efficiency.

When the vehicle operator desires to operate the vehicle on liquidgasoline only, he turns valve 54 to the closed position and turns valve51 to the open position. Conversely, if he wishes to operate the vehicleon gaseous fuel alone, he turns valve 51 to the closed position andvalve 54 to the open position. Similarly, the vehicle can be operated byboth fuel systems simultaneously, by turning both valves 51 and 54 tothe open position.

Since the gaseous fuel mixture is installed into the air intake systembefore the air filter 42 where there is no congestion of engine parts,relatively easy installation of the gaseous fuel mixer can beaccomplished. Moreover, installation into the air intake system is aquick and easy procedure, requiring no significant adaptation ormodification of existing equipment. The same gaseous fuel mixer can beinstalled in virtually all vehicles. Additionally, no precisionmachining is needed to manufacture the gaseous fuel mixer, since anyprecise fuel flow rate can be achieved by simply adjusting the fuel flowregulator.

Because the gaseous fuel mixer is relatively small and mounted to theair intake system before the air filter 42, the gaseous fuel mixer doesnot disturb the existing air flow to any significant degree and thegaseous fuel travels a longer pathway before reaching the pistons andcylinders, thus giving the gaseous fuel and air plenty of time to mixhomogeneously.

The gaseous fuel mixing system of the present invention provides forexceptionally smooth acceleration of the vehicle. Positioning thegaseous fuel mixer before the air filter 42 decreases the influence ofthe engine vacuum on the mixer during engine acceleration due primarilyto (1) the relatively long pathway from the cylinders to the mixer; (2)the substantial air impedance between the cylinders and the mixer; and(3) the relatively large cross-sectional area of the air intake systemwhere the mixer is positioned. Thus, being negligibly influenced by theengine vacuum, the gaseous fuel mixer maintains a constant gaseousfuel/air ratio irrespective of the air flow rate through the air intakesystem, even during engine acceleration.

The following fuel efficiency data was obtained from installation of oneprototype of the gaseous fuel mixer in a 1980 Honda 1500 DX Civic (4cylinders), operating on propane gas:

    ______________________________________                                                        Idle/Cruise                                                                           Full Throttle                                         ______________________________________                                        Air/Propane Fuel Ratio                                                                          14.6/1    14.0/1                                            Carbon Monoxide Emission                                                                        0.5%      1.60%                                             ______________________________________                                    

Since the gaseous fuel/air ratio remains constant, no gaseous fuel iswasted during engine acceleration. Moreover, as the pistons andcylinders require more gaseous fuel/air mixture in response to engineacceleration, the increased demand is met immediately since there isplenty of gaseous fuel already mixed with air waiting to be combusted inthe snorkel 15, the air filter housing 40, the carburetor 44, and allother locations within the engine between the gaseous fuel mixer and theengine cylinders. Because the engine can immediately begin to use thisnearly perfectly mixed gaseous fuel/air reserve to begin acceleration ofthe engine, the gaseous fuel mixer has more than adequate time toreplenish the gaseous fuel/air supply within the engine system, thusnegating the instance of wasted fuel normally experienced during the airresponse delay. Moreover, this "reserve" of gaseous fuel/air mixtureenables the engine to accelerate more quickly and smoothly.

Additionally, the mixing of the gaseous fuel with the incoming air isnot affected by a dirty or wet air filter, or any other impedance of theair flow through the engine system. This is a consequence of positioningthe gaseous fuel mixer within the air intake system before the airfilter 42. If the air flow is impeded by a dirty air filter or otherforeign substance, the gaseous fuel mixer automatically decreases theamount of gaseous fuel released into the air intake system to correspondto the decrease in air flow. Thus, even if the vehicle owner isnegligent with regard to maintenance, the fuel efficiency of the vehiclewill not be substantially affected.

Somewhat surprisingly, impedance of the air flow between the air filter42 and the cylinders actually enhances the efficiency of the gaseousfuel mixer during engine acceleration. Impedance of the air flow betweenthe air filter 42 and cylinders tends to reduce the effect of the enginevacuum imposed on the mixer during engine acceleration, thus makingacceleration a smoother transition. The air filter 42 is especially asignificant factor in retarding the increased air flow through theengine system caused by the engine vacuum during acceleration. Thus,positioning the gaseous fuel mixer before the air filter 42 helps toensure that a constant gaseous fuel/air mixture is maintained.

Another preferred embodiment of the gaseous fuel mixer is shown in FIG.6. This preferred embodiment is similar to the preferred embodiment ofFIG. 3, except that it has a second channel member 70 with a closed end71 in lieu of a cap. This preferred embodiment of the gaseous fuel mixeris thus mounted to snorkel 15 by drilling a single hole in the bottom ofthe snorkel 15. Second channel member 70 is inserted through the hole soas to be disposed within snorkel 15 such that holes 18 face the airfilter 52. The second channel member 70 is then threadingly mounted tofirst channel member 16 and secured to snorkel 15 by a securing nut 72.The preferred embodiment of FIG. 6 operates in substantially the samemanner as the preferred embodiment of FIG. 3, the only importantdifference between the two preferred embodiments being the method ofattachment to snorkel 15 and the method of closing the upper end of thesecond channel member.

Still another preferred embodiment of the gaseous fuel mixer is shown inFIGS. 7 and 8. This preferred embodiment includes a single channelmember 80 having a face 81 with a plurality of holes 82 formed therein.This preferred embodiment of the gaseous fuel mixer is mounted to thesnorkel 15 by drilling a single hole in the bottom of the snorkel 15,positioning channel face 81 within the hole so as to be flush with thebottom surface of snorkel 15, and applying a ring of glue or sodder 84around the channel 80 to secure channel 80 to the snorkel 15. Gaseousfuel is introduced into the channel 80 and flow of the gaseous fuel isregulated by turning stopcock handle 32 in a manner similar to that ofthe embodiment of FIG. 3. Holes 81 provide gaseous communication betweensnorkel 15 and channel 80 so that air flowing through snorkel 15 willimpose a vacuum around holes 82 and draw the gaseous fuel throughchannel 80, out holes 82 and into the snorkel 15 to be mixed with theair therein.

The invention may be embodied in other specific forms without departingfrom its spirit or essential characteristics. The described embodimentsare to be considered in all respects only as illustrative and notrestrictive. The scope of the invention is, therefore, indicated by theappended claims rather than by the foregoing description. All changeswhich come within the meaning and range of equivalency of the claims areto be embraced within their scope.

What is claimed and desired to be secured by United States LettersPatent is:
 1. A system for mixing gaseous fuel with air for subsequentcombustion in an internal combustion engine comprising:a gaseous fuelsource; means associated with said gaseous fuel source to supply gaseousfuel from said gaseous fuel source at atmospheric pressure; an airintake system having an air inlet and an air intake conduit, said airintake conduit being in fluid communication with said air inlet at oneend and with an air filter at the other end thereof; and means foradmitting gaseous fuel at atmospheric pressure into said air intakeconduit for mixture with the incoming air as it passes through said airintake system and said air filter, said means comprising a fluid channelattached at one end thereof to said gaseous fuel source, and at least aportion of the other end of said channel being positioned within saidair intake system upstream from said air filter, and said portioncomprising fluid outlet means oriented within said air intake systemsuch that a partial vacuum will be created in the vicinity of said fluidoutlet means as incoming air flows past said fluid outlet means therebyto draw gaseous fuel into the air flowing past said fluid outlet means.2. A system as defined in claim 1 wherein said fluid outlet means isformed in said channel so as to be opposite the surface of said channelfirst contacted by air passing through said air intake conduit.
 3. Asystem as defined in claim 1 wherein said fluid outlet means comprises aplurality of holes vertically arranged along the side of said fluidchannel.
 4. A system as defined in claim 1 wherein said fluid outletmeans comprises a plurality of holes horizontally arranged in said fluidchannel relative to the air flow through said air intake conduit.
 5. Asystem as defined in claim 1 wherein said fluid outlet means comprises aslit formed in said fluid channel.
 6. A system as defined in claim 1further comprising means for regulating the flow of gaseous fuel throughsaid fluid channel.
 7. A system as defined in claim 1 wherein said fluidoutlet means comprises at least one hole formed in said fluid channel ata position facing away from the surface of said fluid channel firstcontacted by air passing through said air intake conduit.
 8. A system asdefined in claim 6 wherein said regulating means is an adjustable screwmounted to said fluid channel such that a portion of said screw isdisposed within said fluid channel.
 9. A system as defined in claim 6wherein said regulating means is a stopcock mounted to said fluidchannel, said stopcock having a rotatable member disposed within saidfluid channel with a bore formed therethrough.
 10. A system for mixinggaseous fuel with air for subsequent combustion in an internalcombustion engine comprising:a gaseous fuel source; an air intake systemhaving an air inlet and an air intake conduit, said air intake conduitbeing in fluid communication with said air inlet at one end thereof andbeing in fluid communication with an air filter at the other endthereof; and means for admitting gaseous fuel at atmospheric pressureinto said air intake conduit for mixture with the incoming air as itpasses through said air intake conduit and said air filter, said meanscomprising a fluid channel mounted in said air intake conduit such thatone end thereof extends below the air intake conduit and is attached tosaid gaseous fuel source, and the other end thereof extends above saidair intake conduit and is enclosed by a cap, and the portion of saidfluid channel situated within said air intake conduit comprising one ormore small openings formed in said fluid channel and oriented such thata partial vacuum will be created in the vicinity of said openings asincoming air flows past the openings and through the air filter therebyto draw gaseous fuel into the air flowing past said openings.
 11. Asystem for mixing gaseous fuel with air for subsequent combustion in aninternal combustion engine comprising:a gaseous fuel source; an airintake system having an air inlet and an air intake conduit, said airintake conduit being in fluid communication with said air inlet at oneend thereof and with an air filter at the other end thereof; and meansfor admitting gaseous fuel at atmospheric pressure into said air intakeconduit for mixture with the incoming air as it passes through said airintake conduit and said air filter, said means comprising a fluidchannel attached at one end to said gaseous fuel source, and the otherend thereof being positioned within said air intake conduit upstreamfrom said air filter, the end of said fluid channel that is positionedwithin said air intake conduit comprising one or more openings formed insaid fluid channel and oriented within said air intake conduit such thata partial vacuum will be created in the vicinity of said openings asincoming air flows past said openings and through said air filterthereby to draw gaseous fuel into the air flowing past said openings.